The Dungs 217-326A (GMH-A4-4-4) is an SPDT Gas Pressure Switch for automatic burner controls.  The switch is adjustable and has a 1" to 20" W.C. setting range. It does not require auxiliary power and can be easily reset manually. The presence of neon light serves as indicator if the switch is tripped which may be caused by exceeded setpoint or undershot.

The applicable mediums are air, butane, natural gas, propane, and various inert gases.  Must be connected to heating types of equipment with 1/4" NPT pipe.  Also, the switches are calibrated for vertical mounting.

The Dungs offers GAO (Automatic Reset), GMH (High Manual Reset), and GML (Low Manual Reset) A4 Pressure switches for industrial and commercial heating applications such as gas burner controls.  A4 pressure switches are suitable for making and/or breaking a circuit relative to changes in medium pressure relative to the set point. The set point can be set in the field by an adjustable dial with an integrated scale. Test nipple integrated in metal housing to verify setpoint.

Application:

Pipe mount; Calibrated for vertical mounting, set point may change by 0.2" W.C. when mounted otherwise; Screw terminals with 12" NPT Conduit connection; Neon light included.